1. Field of the Invention
The present invention relates to a DC to DC power converter having an input and a load output, the converter comprising a resonant transformer provided with a transformer input and a transformer output coupled to the load output, an output rectifier circuit coupled to the load output, and a transformer control means coupled between the input of the converter and the transformer input. The present invention also relates to a power supply and a battery charger which are provided with such a converter.
2. Description Of the Related Art
Such a converter is known from DE-C-33 00 669 which discloses a converter utilized applied in a DC current power supply. The known converter comprises a resonant transformer in the form of a resonant piezo-electric transformer whose input impedance is connected to a transformer control means in the form of a self-oscillating pulse providing means which provides pulses at a pulse rate which is equal to the resonant frequency of the resonant transformer. An input converter AC voltage is rectified and stabilized and then fed to the resonant transformer through the self-oscillating pulse providing means. The transformer output of the resonant transformer is connected to the output rectifier circuit and a voltage stabilizer circuit to provide a high performance output power at the load output of the converter which is virtually independent of the open or short circuit state of the load. In particular, the known converter provides an alternately operated parallel arrangement of two piezo-electric transformer for enhancing the availability of the output power on the load means. A disadvantage of the known converter is that its flexibility in terms of variability and arrangement of the converter as a whole and the output rectifier circuit in particular is limited.